Clark and Ramsbotham report instances of double conception, one fetus being born alive in the ordinary manner and the other located extrauterine.

Chasser speaks of a case in which there was concurrent pregnancy in both the uterus and the Fallopian tube.

Smith cites an instance of a woman of twenty-three who became pregnant in August, 1870.

In the following December she passed fetal bones from the rectum, and a month later gave birth to an intrauterine fetus of six months' growth.

McGee mentions the case of a woman of twenty-eight who became pregnant in July, 1872, and on October 20th and 21st passed several fetal bones by the rectum, and about four months later expelled some from the uterus.